Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so "Read-only" in the description is pure restatement. What it does add is result content: both prices, in/out-of-stock status, and best price per ounce, which tells the agent what a successful call yields. Since an output schema exists, that return detail is partly redundant, keeping this at a solid but unremarkable 3.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The sentence is front-loaded with the picker identity and the filter axes before the usage cue, and the size examples earn their length. It is slightly overpacked — the site-URL reference and the redundant "Read-only" tail could be dropped without loss.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With 6 optional parameters, full annotation coverage and an output schema, the description supplies what structure cannot: the size token format, result payload contents, and a usage trigger. The only real gap is disambiguating this tool from search_products, which matters given 17 siblings.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is already 83%, so the baseline is 3, and the description clears that bar by documenting the size vocabulary concretely ("1-oz", "1-10-oz", "10-oz", "1-kilo", "1-gram") — something the bare pattern "^[a-z0-9-]{1,20}$" cannot convey. It also glosses the sort dimension by mentioning "best price per ounce", which maps to the ppo/premium enum values. The state parameter (delivery-state shipping rules) is the one input left unexplained by the description.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific verb-and-resource pair (find/list products matching a filter set) and enumerates the filter axes: metal, form, size, purpose, sort order. It is clear what the tool returns (matching Bullion Trading LLC products). It stops short of distinguishing itself from the overlapping sibling search_products, so an agent must guess which filter tool to prefer.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

"Use when the user describes what they want (metal, form, size, budget) and needs matching Bullion Trading LLC products" gives a usable trigger condition. However there are no exclusions and no named alternative, even though the sibling list contains search_products, list_best_sellers, get_deals and get_product, all of which plausibly overlap with browsing-by-desire.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.